With the widespread popularity of portable communication devices such as cellular telephones, there has been an increasing demand for such portable communication devices to operate in more than one user mode. In a first mode of operation, here referred to as a normal-phone mode or private mode, a user first holds the portable communication device away from his ear and enters access information such as a telephone number. The input data can be verified by monitoring the information shown on a display. The user then places the portable communication device close to his ear to engage in a call.
The first mode of operation limits usability; it is sometimes desirable for the user to not have to hold the portable communication device while engaged in a call. For these reasons, a second mode of operation, a hands-free or speakerphone mode, is employed.
In the speaker phone mode, the portable communication device will emit audio information at a louder volume, thus allowing the user to hear information while the portable communication device is away from his ear. However, the continued reduction in size of portable communication devices prohibits the use of conventional acoustic cavity designs otherwise found in speakerphone systems. There, a speaker configuration is needed to provide improved speaker performance in a small packaging envelope.
Devices have been used to linearly protrude a speaker from an available housing. However, these devices can not be used when the housing size is too small, such as in a wristphone.
In addition, when the portable communication device is in the speakerphone mode while it is close to the user's ear, acoustic shock to the user's hearing system could result. Therefore, a highly reliable mode switching system is needed to switch the phone between the normal-phone mode and the speakerphone mode of operation.
Proximity detector systems have been used to switch a portable communication device between the private mode and the speakerphone mode. These systems depend on having the phone near the users head. However, these would not work on a handsfree phone or a small device such as a wristphone.
Hinged or clam-shell type phones have developed a system where the position of the hinge directs whether the phone operates in private mode or the speakerphone mode. However, this system would not work on a one-piece phone, or other non-hinged phones such as a wristphone.
Other limitations of prior art wristphones are the upper limits placed on the achievable acoustical quality and loudness. As portable communication devices such as wristphones become smaller and thinner, space necessary for acoustical baffling, resonance, and isolation between the front and the back sides of the speaker diminishes. In addition, the speakers themselves get smaller. Voice quality is thus degraded. And although the speaker performance may be adequate for privacy mode conversation, speaker performance is not adequate for speaker phone operation.
Accordingly, there is a need for a portable communication device with a speaker enclosure that provides improved speakerphone performance as well as privacy mode performance. In addition, there is a need for a speaker enclosure that can be used to select between privacy and speakerphone operation. There is a further need for improved acoustics for better sound quality during speakerphone mode. In addition, there is a need for portable communication device that is configured as a wristphone with a speaker enclosure that provides a speakerphone mode.